Topic : Carbon Mast Longevity

Can you leave a carbon rig, set up, on the boat in the boat park like you can an alloy set-up or will it deteriorate quickly?

Posted: 03/09/2013 18:15:11
By: Alan3463
Keep on top of this varnish and it'll be fine. Yet resin degrades under uv light so only use good quality two pack pain or varnish and put a coat on every 18 months to two years touching up damage in the meantime

Posted: 03/09/2013 20:38:11
By: Chris M
NB. Not all two pack varnishes are UV impermiable.

Posted: 03/09/2013 20:58:49
By: .....
I would try and avoid leaving it under any load as well, standing rigging snugged up but not much more.

Posted: 03/09/2013 21:01:10
By: ( : )
Yes if leaving up in the dinghy park, try and leave with minimum rig tension as over time it may have an effect on the mast's racing pedigree. If we leave our mast out with the b14 at Whitstable, we put it in its weatherman cover fot the week. I would also do the same with my M relinquish mast as well unless sailing the next day.  Hope that helps.

Posted: 03/09/2013 21:26:41
By: Barnsie
If making a helpful comment why not say who you are? You might get bought a beer if you're lucky.

Posted: 03/09/2013 21:35:47
By: ....................
What's best white paint or varnish,  what are the signs of a mast being affected by uv

Posted: 03/09/2013 21:36:43
By: Megan
Paint will be almost totally UV proof. However it does become tatty quite quickly.

In my experience, if you keep on top of the varnish it's fine. My older mast is now 10 years old and has not gone yellow, the sign of UV damage to the resin. You do need to use two pack, and it does need to be good quality. I like the Epifanes personally.

In the grand scheme of things it probably doesn't really make much odds as long as you keep the spar coated and touch in damage as it needs in. on that basis i'd stick with varnish as it won't go tatty and you can see whats going on underneath.

Posted: 03/09/2013 21:50:36
By: Chris M
Agree with the last post on that one. Painted covers a multitude of sins, but white is less hot than black. I stick to the lacquared/varnished version

Posted: 04/09/2013 11:15:07
By: mark barnes
You can always paint your mast black

Posted: 31/05/2015 12:56:11
By: Gareth Griffiths NHRC
Just did a fantastic tuning coaching session with Richard Whitworth at Lymington town SC yesterday... 

I am having some issues with rig tension and asked Richard his opinions... 

I am now wondering has anyone found that their ageing carbon mast gets tired and loses its design characteristics, stiffness in the right places while flexing in others.

On my boat, Merlin Rocket 3450 the rig tension is applied to the shrouds, which ineffect pulls on the forestay to give me a tight luff on my jib. Same system as most one string modern merlins. E.g. I followed KC's excellent diagrams.

At the moment when rig tension is applied it is compressing the mast and not tensioning the forestay. 

This was varified as well by having a RW coaching in a rib following us upwind in 15-20 kts yesterday.

There are other factors that I am considering that could have cause and effect on rectifying the situation. But I am really far more interested, first of all, in people's thoughts on whether they have noticed softening in the properties of their rigs over time.

My mast is a Chipstow, full carbon, carbon spreaders wire rigging.

Hull is tested up to 450kgs and is not giving a millimetre. Ad,itedly a wooden boat will never be as stiff as a modern composting boat but hull flex is not my consideration, want to know more about experiences of carbon spars degrading with age.

Might get my mast ultrasounded to look for issues.

Posted: 31/05/2015 13:02:12
By: Gareth Griffiths NHRC
Have you measured the shroud base? If it's further forward this may have an effect.
Regardless of the design characteristics of the mast, if rig tension is not tensioning the forestay there is something very, very wrong somewhere. Composting may be an issue as it is pretty soft.
My spare Chipstow is now 12 years old. When i put it on i don't notice any differance. My personal opinion on alleged mast softening is that the tube itself is pretty solid, but the track is vulnerable and if there is significant damage to the track it will affect the whip characteristics of the spar.
That however doesn't sound like your problem. 

Posted: 31/05/2015 19:19:39
By: Chris Martin
My 1st generation SuperSpars has not changed at all through the 15 years of my ownership and remains pretty stiff in the lower sections and incredibly robust.  It has spent all it's life outside, generally rigged but without any tension applied if it is in the boat.  I think it dates from 1998 when Hywel broke an alloy mast on Elusive and replaced it with carbon and I bought it with Elusive and transferred it to Heaven Sent in 2002.

Posted: 31/05/2015 20:49:29
By: AndrewM
Morning Chris and Andrew.

Shroud base, foot and distance to fore stay are all same as the winder set up. Have slightly different spreader angles but geometry is easy to configure.

It is the tubes toughness that is what I need to know.

Interesting what you said about the sail track... That might be an issue. Though having made a few repairs to the sail track it should be stiffer if anything.

Regarding the fatiguing of carbon, so far as I have read and been told by experts, carbon doesn't fatigue.

Epoxy does and UV is the main factor.

Mast has always been painted rather than lacquered so not an issue.

Maybe worth ultra sounding it for cracks, de-lam or voids...

Posted: 01/06/2015 07:07:35
By: Gareth Griffiths NHRC
I don;t think that the mast is a problem, I think you have a fundamental issue with something running out of travel.
If the leeward shroud is going tight and the jib luff is bending off something is wrong. If the shrouds are tight then the forestay must be too, unless something is preventing it. The spreaders being ridiculously long, or the shroud base being a long way forward might cause this, but if you've a standardish set up then it won't be that.
If the mast has lost a bit of it's spring over the years it will still behave as a normal mast, just not as "flicky". It will still hold rig tension on all three wires.
I would arm myself with a loos gauge and check the rig tension on all three wires right across the rake range. My guess is that all will be well at upright, but something (Ferrule?) is getting stick in the mast at or approaching full rake. You probably won't need the loos actually, the problem will probably reveal itself reasonably quickly! 

Posted: 01/06/2015 08:03:47
By: Chris Martin

  A quick web search finds Fatigue in Composites edited by Brian Harris  which appears to be a detailed (700 pages of text and complicated maths) examination of the issues of fatigue in Carbon and other composite structures. The first 160 pages seem to be available on line. He seems to conclude that this stuff wears out then it breaks, much like anything else. Just when it breaks depends upon how over (or under) engineered it was in the first place.

Surely it is inevitable that over the years constant bending will result in some delamination of resin from the fabric and some damage to the strands. There are certainly plenty of broken bicycles around that seem to bear this out!

Posted: 01/06/2015 12:42:52
By: Edward 3340

There are a number of factors to composites changing! - A delamination is most common! But this usually results in a rapid catastrophic failure.

The others include UV degredation of the polymer component(Why people paint them white and re varnish them with UV stable resins), microfracture from stress etc, and heat damage as the resins don't like getting too hot as well. - again white masts get less hot than lacquered black ones.

However the bendiness of the mast can be increased due to track wear as it is an integral part of the structure I had this with my Chipstow, when Jacko replaced the track the stiffness returned!

Posted: 01/06/2015 13:10:00
By: Piers
Thanks for your responses..

Chris this is more about carbon than rigging, trust me when I say that this is not a system issue blocks all run fine none deadend where unwanted.... 

There are adjustments to lowers and spreader geometry that I am experimenting with this week to help increase pull on the forestay.

But I returned to this post to ask what people had experienced with their carbon masts over time.

Posted: 01/06/2015 19:17:12
By: Gareth Griffiths NHRC
Hi Edward

Yes I have read a fair bit of Brian Harris work, he is often quoted in other books too...

The basis concludes with most other texts. Degradation starts with epoxy and ends with the laminates disintegrating in one of several forms...

Thanks for digging it out.

Posted: 01/06/2015 19:23:12
By: Gareth Griffiths NHRC

I'm starting to think the track damage maybe a bigger factor than first imagined. It's been professionally repaired by one of the best guys in the business but, the cause of the track damage may have caused in foreseen issues.

If the track was damaged because the previous owner turned turtle and bounced on the bottom or had the mast stuck in the mud and yanked it out with a rescue rib all sorts of damage might have been done.

Posted: 01/06/2015 19:29:16
By: Gareth Griffiths NHRC
I cannot rationalise why a soft, damaged mast will not allow you to tension the forestay unless something is tearing down the mast - which i assume you'd have spotted.
A soft mast will be, well, soft. It will overbend in the gusts and it may adopt too much prebend for a given rig tension. But if the shrouds are tight, so will be the forestay. It has to be unless something is physically preventing the wire from taking up tension - I assume you have a 2:1 on the halyard?
There are hundreds of Chipstow masts out there, and many have been repaired - noone else has reported this problem. There are in all likelihood even more old Superspars out there too - again noone has reported this issue.
I'm certain you're barking up the wrong tree - check the simple things first :) 

Posted: 01/06/2015 20:04:09
By: Chris Martin
Thanks Chris..

Your thoughts are duly noted.

Buy me a beer at the nationals and I'll explain it to you

Posted: 01/06/2015 20:59:36
By: Gareth Griffiths NHRC
Gareth,  I agree with Chris re the forestay not being tensioned. Something is  not doing what it should. Are the spreaders angled correctly, they could be trying to bend mast backwards ending up with just compression. Think you'd notice that though.
On mast deteriation, mast on 3646 is 10 year old Superspars and haven't noticed and strange behaviour. Except when a shroud gave way and it bent like a banana. Mast on 3542 Chipstow, the repaired one, seems fine. Apart from me not having enough lowers on at Bala, It's curve seemed pretty much the same as Chris's.

Posted: 02/06/2015 09:43:00
By: Miles
As a general observation and unrelated to Gareth's specific problem I have to say that I have been surprised at how quickly unprotected epoxy deteriorates when exposed to sunlight. I have used it extensively to protect timber joinery in sliding sash windows. Where it is painted it has worked fine. Unprotected on the sides of the sash boxes and exposed to lots of south facing sun it has a very short life. Keep those masts painted and you should be ok. White seems the best option to me as epoxy starts to soften above 90 degrees Celsius and a black surface will get hot much more quickly. Just think how hot black cars get in the sun.

Posted: 02/06/2015 11:22:30
By: Edward3340


It is very unlikely the main tube has gone soft to a large extent - damage to the lay up takes a long time - Chris is right you seem to be too focused on this and need to look at the simple issues first in my opinion (my Father helped develop composites and epoxies and taught me a lot!)

You need to understand the track issue is not just from damage - it is from the track wearing  every time you pull sails up and down - gradually the track gap gets bigger . I got this info from Alan Jackson himself.

Thus when you bend the mast this track has to close onto the sail to an extent. If the track is worn less material = less stiff PLUS more bend as not gripping sail as much - the whole track needs replacing - top to bottom to get the stiffness back.
Talk to Dave Winder he replaced his Chipstow track as mast 'soft' and stiffness returned! 

Posted: 02/06/2015 11:43:51
By: Piers
Cheers guys...

The reason I am focusing on asking about fatigue on the rig is to try and exonerate that as a likely factor.

I will play with the geometry and running rigging this week to try to illeviate and improve.

I posted a similar thread on and have had a few emails from various types of skiff sailors who have noticed similar deteriation in tubular booms.

Could be uv, could be structural integrity diminishing, so I am not ruling this element out.


Interesting to hear Dave replaced his luff track. If other factors don't solve the lack of transferring tension through the rig to the forestay then I may look at replacing the track later this year...

Posted: 02/06/2015 19:19:18
By: Gareth Griffiths NHRC
Cheers guys...

The reason I am focusing on asking about fatigue on the rig is to try and exonerate that as a likely factor.

I will play with the geometry and running rigging this week to try to illeviate and improve.

I posted a similar thread on and have had a few emails from various types of skiff sailors who have noticed similar deteriation in tubular booms.

Could be uv, could be structural integrity diminishing, so I am not ruling this element out.


Interesting to hear Dave replaced his luff track. If other factors don't solve the lack of transferring tension through the rig to the forestay then I may look at replacing the track later this year...

Posted: 02/06/2015 20:50:09
By: Gareth Griffiths NHRC
Hi guys

So I have shortened the lowers. Will see tomorrow night if that transfers tension to the forestry.

Posted: 16/06/2015 19:15:01
By: Gareth Griffiths NHRC
Hi Gareth,
Suggest checking your spellchecker as well as you don't want problems with slack forestry in the middle of the Solent! 

Posted: 16/06/2015 23:49:15
By: AndrewM
Well spotted...!

I can't even imagine the litagation involved with altering the forestry in the new forest council while only trying to get more forest at tension.

Lowers first, then I'll look at spreaders if no results.

Posted: 17/06/2015 10:13:11
By: Gareth Griffiths NHRC
Lowers made a difference. Great sail at Lymington last night.. 

Going to look at the spreader angle next

Posted: 18/06/2015 10:25:26
By: Gareth Griffiths NHRC


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